Enforce using six.text_type() over unicode()

For python 3 compatibility, this adds a hacking check to prevent the
usage of unicode().

Change-Id: I791bbf251ac0f9615a9bedc2dd295a7982d72e0a
Closes-bug: #1282893

HACKING.rst

@@ -15,3 +15,4 @@ glance Specific Commandments
 - [G318] Change assertEqual(A, None) or assertEqual(None, A) by optimal assert like
   assertIsNone(A)
 - [G319] Validate that debug level logs are not translated
+- [G320] For python 3 compatibility, use six.text_type() instead of unicode()

glance/hacking/checks.py

@@ -40,6 +40,7 @@ asse_equal_end_with_none_re = re.compile(
     r"(.)*assertEqual\((\w|\.|\'|\"|\[|\])+, None\)")
 asse_equal_start_with_none_re = re.compile(
     r"(.)*assertEqual\(None, (\w|\.|\'|\"|\[|\])+\)")
+unicode_func_re = re.compile(r"(\s|\W|^)unicode\(")
 
 
 def assert_true_instance(logical_line):
@@ -91,8 +92,18 @@ def no_translate_debug_logs(logical_line, filename):
             yield(0, "G319: Don't translate debug level logs")
 
 
+def no_direct_use_of_unicode_function(logical_line):
+    """Check for use of unicode() builtin
+
+    G320
+    """
+    if unicode_func_re.match(logical_line):
+        yield(0, "G320: Use six.text_type() instead of unicode()")
+
+
 def factory(register):
     register(assert_true_instance)
     register(assert_equal_type)
     register(assert_equal_none)
     register(no_translate_debug_logs)
+    register(no_direct_use_of_unicode_function)

glance/tests/test_hacking.py

@@ -51,3 +51,14 @@ class HackingTestCase(utils.BaseTestCase):
 
         self.assertEqual(0, len(list(checks.no_translate_debug_logs(
             "LOG.info(_('foo'))", "glance/store/foo.py"))))
+
+    def test_no_direct_use_of_unicode_function(self):
+        self.assertEqual(1, len(list(checks.no_direct_use_of_unicode_function(
+            "unicode('the party dont start til the unicode walks in')"))))
+        self.assertEqual(1, len(list(checks.no_direct_use_of_unicode_function(
+            """unicode('something '
+                       'something else"""))))
+        self.assertEqual(0, len(list(checks.no_direct_use_of_unicode_function(
+            "six.text_type('party over')"))))
+        self.assertEqual(0, len(list(checks.no_direct_use_of_unicode_function(
+            "not_actually_unicode('something completely different')"))))